PhD, 2nd year
Project: Unexpected stoichiometries in the Ca-O system.
Calcium and oxygen are amongst the most abundant elements in the Earth’s interior. CaO is a widely used compound formed from these elements and is very stable at ambient pressures. Although the crystal structure and chemical composition of CaO seems to be simple and well understood, metastable or stable Ca-O compounds with counterintuitive stoichiometries may exist at high pressures. In this work, ﬁrst-principles density functional theory calculations and ab intio evolutionary simulations have been used to predict high pressure Ca-O structures. I have shown that under pressures as low as 10 GPa and as high as 200 GPa the stability of the Ca-O system changes and new materials emerge with diﬀerent stable or metastable structures. In addition to CaO, I theoretically predicted stable structures for Ca, Ca2O, Ca2O3, Ca3O, Ca3O2, Ca7O, CaO2, CaO3, CaO7, and O at various high pressures. Electronic and structural properties have also been determined using computational methods.
The next evolutionary state of this project will be to reproduce these computational results in the laboratory.
- B.S. in Physics, spring 2013
- M.S. in Physics, spring 2016
- Ph.D. in Physics, expected spring 2020
- Livermore National laboratory collaboration in shock physics
Professional schools & workshops:
- High Energy Density Summer School with Paul Drake 2016
- Extreme Crystals Weekend 2015, 2016
- Bob Davis Scholarship 2011-2013
- UNLV Grant 2011-2013
- NASA Space Grant Scholar 2011-2012
In revision- Ab Initio Structure Predictions for Calcium Oxide at High Pressures, Christopher A. Higgins, Changfeng Chen
- Gordon Research Conference, Holderness New Hampshire 2016
- Poster presentation on high pressure Ca-O system
- NNSA SSAP Symposium, Bethesda MD 2016
- Poster presentation on solid lithium based electrolytes was presented.
- NNSA SSAP Symposium, Santa Fe NM 2015
- Poster presentation on computer simulations, evolutionary algorithms and structure changes
- HiPSEC annual meeting, Las Vegas NV 2015
- Poster presentation of my theoretical work with calcium oxide.
- HiPSEC annual review, Las Vegas NV 2014
- Presentation on theoretical work with sodium chloride and calcium oxide.